


Unwelcome Urges

by AlliterationNation



Category: Granblue Fantasy (Video Game)
Genre: Dubious Consent, F/M, Feower in heat, Knotting, Mating Cycles/In Heat, Plot What Plot/Porn Without Plot, Sibling Incest, Strap-Ons, Trans Feower, Trans Male Character, Vaginal Sex
Language: English
Status: Completed
Published: 2020-12-23
Updated: 2020-12-23
Packaged: 2021-03-11 02:54:25
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,126
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28267974
Author URL: https://archiveofourown.org/users/AlliterationNation/pseuds/AlliterationNation
Summary: Feower goes into heat. Tien suggests an unconventional way of dealing with it: fuck him herself until he snaps out of it...
Relationships: Feower/Tien (GBF)
Kudos: 7





	Unwelcome Urges

“Feower,“ Tien said. “You're in heat, aren't you?“

“What? No,“ Feower lied. He'd woken up with that god damn heat between his legs this morning- that, and the conviction _not to let Tien know_. He'd told her during his last - and first - Erune heat, and swiftly regretted it. 

Tien frowned. “Mm. Really? Is that why you keep shifting in your seat, and staring after every Erune man passing by?“ 

“I'm only staying alert.“ The cafe they had visited lay in a small town they'd stopped by on Eternal business. Feower had protested having both of them leave Stardust Town at once, but it couldn't have been helped. At least they were about ready to go back now, finally… 

The look Tien gave him made it clear that she didn't believe him. Damn it. 

“You can't just ignore it, Feower. Didn't the last time teach you that?“

Feower grit his teeth. “Don't remind me.“ 

“We can stay here a little longer while we find you someone to take care of it with-“

“I'm _not_ in heat, Tien.“ Even as he said it, the almost painful throbbing between his legs grew even worse. “We can go home without delay.“ 

Just then, a tall Erune man happened to walk past where they sat. Without wanting to, Feower turned his head to look after him, his head filling with images of wrapping his legs around him while he was stuffed full with cock-

“Are you done pretending?“ Tien leaned forward. “I've been dealing with this for longer than you have. It gets easier when you just accept it and find a way to relieve yourself.“

That much was true. Tien's heats had started two years ago, much earlier than Feower's. She hadn't let on how awful they truly were. 

“It isn't good for you to ignore...“

“I _know_ ,“ Feower said. What was the point in pretending if he wasn't going to convince her? “But I'm not going to go and… give myself to some complete stranger. I don't know how _you_ do it all the time, sis.“ 

“Mm. You could find someone you know, then. Seox-“

“No.“ Feower squinted at his sister. “And you are _not_ hiring someone to shove his cock into my face until I can't contain myself anymore this time.“ He shouldn't have said that. The memory of that night only made his arousal worse. He crossed his legs, then uncrossed them again when he saw the look on Tien's face. “I'll find a way to deal with it, okay? I don't need your help.“ 

Thankfully, Tien dropped the subject after that. Maybe she still felt bad for what she'd done. 

–

By the time they checked into an inn on the way home the next day, Feower was just about ready to scream. Ignoring the heat away really wasn't working as well as he'd hoped. It would vanish within a few days even if he did nothing about it, he knew that… but he was beginning to doubt he'd last that long without doing something stupid. 

The fact that he and Tien would have to share a room as the inn was otherwise fully booked didn't help. Masturbating only brought temporary relief, but he'd been looking forward to that much and now… he cast a glance at his sister, who was bent over her travel bag and rummaging through it. He could hardly do that now, could he? 

Unbidden, his thoughts trailed over to the group of drunk Erune men who'd been sitting downstairs, and how it would feel to be mounted by them, one after another… 

Fuck. He needed something to fill his aching cunt, and he needed it _now._

“Right,“ he said, trying to keep his voice steady as he turned away and made for the door. “I'm going to go d-“

“Mm. Hold on.“

Feower's question died on his lips when he turned his head and saw the oversized dildo in her hand, complete with a giant knot at the end. 

“I'm not going to let whatever Erune man you run into next take advantage of you,“ Tien said. “And if you won't find someone to relive yourself with safely, then we'll just have to do the next best thing.“ 

“The next best… you want me to put that into my…?“ He would never say it outloud, but the thought was appealing. He couldn't take his eyes off of the dildo. That thick tip pushing into him… 

“Mm, no,“ Tien said. “You doing it yourself won't help much. Trust me, I tried.“ She strapped the dildo onto herself. “I'm going to do it for you. Lie down. You'll feel better afterwards, I promise.“ 

Feower's desire to bolt and get out of this situation collided with intrusive thoughts about how amazing it would feel to be fucked raw, and did it really matter _who_ was doing it? He couldn't take his eyes off of the dildo jutting out so enticingly from his sister's groin… 

“I probably really would have thrown myself at the first guy I meet,“ he muttered. 

“That's right. Isn't this better?“

Maybe it was. Maybe it wasn't. He didn't care anymore. If this went on any longer, he'd lose his mind and do something stupid. “This doesn't leave this room,“ he said as he trudged back over to the bed, pulled down his pants and laid down with his ass up in the air. He'd instinctively taken that position during his last heat as well. Apparently that was just how it worked. The pose emphasised to him how _empty_ he was, and how wrong that felt. 

He couldn't see what Tien was doing, facing the wall as he was. The finger pushing into him took him by surprise. He hissed and clamped down on it. Too small to be satisfying, but it was _something_ to begin scratching that awful itch. “Stop drawing this out,“ he growled. “Fuck me properly already.“

“I just needed to check if you're ready to take it.“ Tien withdrew her finger. A moment later, the tip of the dildo replaced it. Feower froze up while she worked it into him. It was _huge_ , even bigger than the guy she'd paid off to fuck him last time, and it felt fucking amazing. Despite everything, he hadn't realised how badly he'd needed to get bred by a fat Erune cock. 

Now that Tien had pushed the tip inside, she wasted no time before harshly thrusting deeper. White-hot lust clouded Feower's mind, It was all he could do to stop himself from begging for more. Fortunately, he didn't have to. In his feverish mind, it felt like there was a limitless amount of cock being forced into him. By the time Tien bottomed out, he'd squeezed his eyes shut and panted into the pillow. 

And then Tien began fucking him in earnest. 

She pulled out and then shoved the dildo back into him all the way, taking a brutal pace that barely left him able to breathe. Every time she thrust forward, he felt the thick knot against his body, even though she didn't try to force it in just yet. He pushed back against her, damn it, he _wanted_ to take it, but she pulled away. 

“Not yet.“

“Then hurry the fuck up!“

Dimly, it occurred to Feower how messed up it was that he was urging his own sister to fuck him. The last few of his braincells that weren't consumed with lust wanted to laugh hysterically. The rest of them didn't care one bit as long as she didn't stop shoving her cock into him. He writhed under her, drooling onto the pillows as the heat consumed his entire body. 

How long this continued, he wouldn't be able to say later on. Before long, though, Tien came to a halt for a moment after bottoming out once again… and then pressed further. 

“This might hurt a bit, but relax. You can take it.“ 

Feower's eyes widened. The knot. That was the knot. Even though only a fraction of it had breached him, it already stretched him out so much further than just the cock had. It did hurt. It felt as if he was being torn in half, but even if he'd wanted to, he couldn't have pulled away. His body had gone limp at the intrusion. All he could do was twitch feebly as Tien pushed deeper and deeper. 

It was so much bigger than that of the Erune who'd deflowered him during his last heat… 

Then the knot reached its widest point, and the rest of it was practically sucked into his body. It pushed Feower over the edge into the deepest throes of an earthshattering orgasm. His back arches as he pushed back, desperate to get just one more inch inside of him, just a little more, a little deeper, all the while making the most obscene noises… 

When he came to his senses again, he was trembling and gasping for breath. His body still clamped down on the knot, in a futile effort to keep the nonexistent come inside. Not that it would have mattered either way. He wasn't fertile. It wasn't fair that he was still plagued with the urge to mate… 

“Are you doing okay?“

“Yes,“ Feower mumbled. The brief lull in arousal wouldn't last, of course. Soon enough, his body would ramp up for another round. Erune mating was never over quickly. He'd learned the last time not to be fooled into thinking he was done. In a few minutes, he'd relax, allowing his sister to pull out and fuck him a second time. In a proper mating, the amount of repetitions depended on the penetrating partner's stamina. Here, though…?

“How often are we going to do this?“

“Two more times at minimum, to properly tire you out,“ Tien said. 

Two more times of his sister fucking him until he couldn't think straight anymore. The thought shouldn't arouse him, but it did. Slowly, he relinquished his hold on the knot, allowing Tien to pull it out. Immediately, he felt awfully empty, like some essential part of him was missing. 

He closed his eyes and braced himself for the second round. 

–

Later, after Tien had unequipped the dildo and draped a blanket over him, Feower opened his eyes again to her touching his face. 

“How do you feel now?“

Relieved. Exhausted. Overwhelmed. Sore. Feower shrugged. “I guess it did the job...“ 

Tien sat down on the bed next to him. How could she be so nonplussed over this all? They'd just had sex. She'd just fucked her own brother. “I can give you the addresses of a few trustworthy Erune who can help you deal with your heats from now on.“

“The same ones who fuck you when you get yours?“

Tien nodded.

“I don't want to.“ Feower sighed. “I know I have to take care of it somehow, but...“

“What about it bothers you so much?“

It was weakness, plain and simple. It meant giving himself over into the mercy of another while degenerating into some… insatiable cockslut. He didn't want anyone to see him like that. Waking up after that man Tien had paid off had used him for hours had been mortifying. 

“Do you want me to keep doing it then?“ Tien asked when he didn't answer.

Feower looked up at her. “You're suggesting to fuck your own twin brother on the regular.“ 

Tien shrugged. “Someone has to, or you're going to get yourself in trouble if you don't lock yourself away for an entire week every month. Besides, I'd be lying if I said I did not find you attractive.“

She said it so casually, admitting she found her own brother hot. Feower knew he _should_ be weirded out by that, by all of this really, but he wasn't. Maybe it was the exhaustion, maybe it was the lingering heat… or maybe it was the truth he'd never wanted to admit to himself, namely that he had also had less than appropriate thoughts about his sister before. 

“Deal, he said a few moments later. “I'll let you take care of me next time… or take care of you, if you want.“ Why not offer? It wasn't like it was any weirder than what had just happened.

“Oh,“ Tien said, glancing away. “I like waking up as a sloppy mess afterwards, actually...“ 

“Suit yourself then.“ He _almost_ understood that. Certainly he'd had fantasies of being pumped full with come during the past two days, and he did maybe miss the feeling of it gushing out of him that he'd had last time. 

Maybe one day he'd take her up on her offer to hook him up. 

For now, he said, “Hey, sis?“

“Yes?“

“Let's do four rounds next time.“


End file.
